Performance of gadoxetic acid MRI and diffusion-weighted imaging for the diagnosis of early recurrence of hepatocellular carcinoma.

To determine the diagnostic accuracy and predictive value of gadoxetic acid liver MRI (Gd-EOB-DTPA MRI) alone or in combination with diffusion-weighted imaging (DWI) as a second-line tool for detecting early hepatocellular carcinoma (HCC) recurrence in cirrhotic patients with previous HCC treated with resection or ablation. Between 2014 and 2017, we prospectively included 34 cirrhotic patients with complete response to resection and/or ablation of early HCC in whom a new focal lesion enhancing in the arterial phase without washout was detected during follow-up with EC-MRI. After signing the informed consent, all patients underwent DWI and Gd-EOB-DTPA MRI; two readers analyzed signal intensities on each phase of dynamic study and on DWI. The final diagnosis was established by histology or follow-up EC-MRI. We used cross-tabulation to calculate indices of diagnostic accuracy. We evaluated 34 patients (7 women; 73.5% with hepatitis C virus) with a total of 53 new arterial-phase-enhancing foci (median size, 10 [IQR 9-14] mm). The final diagnosis, reached by histopathology in 15 (35.7%) lesions and EC-MR follow-up in 27 (64.3%), was HCC in 42 (79.2%) and benign conditions in 11 (21.8%). Hepatobiliary-phase hypointensity on Gd-EOB-DTPA MRI plus hyperintensity on DWI yielded 54.8% sensitivity, 90.9% specificity, 95.8% positive predictive value, and 34.5% negative predictive value for diagnosing HCC recurrence. Among potential indices, combining hypointensity on hepatobiliary-phase Gd-EOB-DTPA MRI and hyperintensity on DWI has the highest specificity and positive predictive value to optimally detect HCC recurrence prior to confident diagnosis by conventional imaging criteria on EC-MRI in cirrhotic liver. • In patients at risk of HCC recurrence, the use of gadoxetic acid liver MRI and DWI may improve the differentiation of unspecific new arterial-enhancing foci from early hypervascular HCC recurrence in patients with non-conclusive findings on extracellular liver MRI. • Combined findings on hepatobiliary-phase gadoxetic acid-enhanced liver MRI and DWI had high specificity (90.9%) and positive predictive value (95.8%) for detecting early hypervascular HCC recurrence, but limited sensitivity. • Combining hepatobiliary-phase hypointensity on gadoxetic acid MRI and hyperintensity on diffusion-weighted imaging allows early diagnosis of hypervascular hepatocellular carcinoma and may help select patients for salvage therapy.